During operation of a power supply device mounted on a vehicle, there is an excessively large amount of heat generated by loss, and the like, of an electronic component, e.g. a switching element, inside the power supply device. Therefore, various kinds of cooling methods are considered from a purpose avoiding damage and the like by overheating of the power supply device.
According to an exemplary method for cooling an electronic component mounted on the substrate inside a power supply device, a substrate, on which a component generating a large amount of heat (e.g. semiconductor) is mounted, is placed on a base plate having a coolant channel formed therein, for example. The same method is also used when cooling a coil component including a core such as a transformer or an inductor (for example, refer to Japanese Laid-open Patent Publication No. 2013-58556).